1,3,5-tris(3-mercaptopropyl)-1,3,5-triazinane-2,4,6-trione

Endpoint summary

Description of key information

The toxicity of 1,3,5-Tris-(3-mercaptopropyl)isocyanurate was tested according to OECD guidelines 201, 202, and 203 for acute toxicity studies with algae (Pseudokirchneriella subcapitata), aquatic invertebrates (Daphnia magna), and fish (Gobiocypris rarus).

Toxic effects to all three species were determined as following:

96-h LC₅₀(G. rarus) =                   0.05 mg/L [95 % C.I.: 0.04 to 0.06 mg/L]

72-h ErC₅₀ (P. subcapitata) =    1.26 mgL [95 % C.I. = 0.97 – 1.63 mg/L]

48-h EC₅₀ (D. magna) =              2.83 mg/L [95 % C.I.: 2.30 to 3.55 mg/L]

 

As the substance was not stable over the time of exposure, all effect values are reported based on measured concentrations of the parent molecule.

Additional information

Toxicity to invertebrates:

Daphnia magna Straus was exposed for 48 hours to 1,3,5-Tris-(3-mercaptopropyl)isocyanurate in a semi-static short-term toxicity study according to the OECD guideline 202 (2004) and in compliance with the OECD-GLP principles. The test concentrations were determined analytically by LC-ESI-MS/MS. A potential degradation product was discovered though could not be determined or quantified. As the measured test item concentrations are not within ± 20 % of the nominal loading rate, according to OECD 202 (2004) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations. Based on the immobilisation of the daphnids the following effect values were derived:

48-h EC₅₀= 2.83 mg/L [95 % C.I.: 2.30 to 3.55 mg/L]

48-h EC₁₀= 1.45 mg/L [95 % C.I.: 1.05 to 1.82 mg/L]

48-h NOEC = 0.57 mg/L

48-h LOEC = 2.06 mg/L

 

Toxicity to algae:

The freshwater algae Pseudokirchneriella subcapitata was exposed to 1,3,5-Tris-(3-mercaptopropyl)isocyanurate for 72 hours in a static toxicity study according to the OECD guideline 201 (2006) and in compliance with the OECD-GLP principles. The test concentrations were determined analytically by LC-ESI-MS/MS. A potential degradation product was discovered though could not be determined or quantified. As the measured test item concentrations are not within ± 20 % of the nominal loading rate, according to OECD 202 (2004) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations. Based on the growth rate of the algae the following effect values were derived:

72-h E_rC₅₀= 1.26 mg/L [95 % C.I. = 0.97 – 1.63 mg/L]

72-h E_rC₁₀= 0.33 mg/L [95 % C.I. = 0.26 – 0.41 mg/L]

72-h NOE_rC = 0.15 mg/L

72-h LOE_rC = 0.51 mg/L

During the pre-tests for the studies with Daphnia magna and Pseudokirchneriella subcapitata, an unknown potential degradation product (probably an oxidation product of the test item, according to the sponsor) with a similar mass as the test item was observed as a second peak in the chromatogram diluting directly after the test item. This potential degradation product was not identified until this study was conducted. The potential degradation product could not be identified (additional equipment, resources and experience with regards to the behavior of the test item in the test solution (e.g. kinetics) would be required), the results are therefore based on the parent molecule.

 

Toxicity to fish:

Gobiocyprus rarus individuals were exposed for 96 hours to 1,3,5-Tris-(3-mercaptopropyl)isocyanurate in a semi-static short-term toxicity study according to the OECD guideline 203 (1992) and in compliance with the OECD-GLP principles. The test concentrations were determined analytically by LC-MS/MS. A potential degradation product was discovered though could not be determined or quantified. As the measured test item concentrations are not within ± 20 % of the nominal loading rate, according to OECD 203 (1992) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations. Based on the mortality of the fish the following effect values were derived:

96-h LC₀= 0.026 mg/L

96-h LC₅₀= 0.05 mg/L [95 % C.I.: 0.04 to 0.06 mg/L]

96-h LC₁₀₀= 0.18 mg/L

As the test item is not rapidly dissolved in water or medium resp., the Fish, Acute Toxicity Study was conducted applying a solubilizing agent: Dimethylformamide (DMF). This study reported also a possible oxidation of the parent compound. Analytical qualification or quantification of the degradation product was not possible in all present studies.

The most sensitive effect value was derived in the Fish, Acute Toxicity test with a 96 -h LC₅₀ of 0.05 mg/L. Based on this value the test item is classified as Aquatic Acute 1 and Aquatic Chronic 1 according to CLP regulation (EC) 1272/2008.